Temperature and humidity control system and control method

Abstract

The present invention relates to the field of HVAC automation technology, and specifically to a temperature and humidity control system and a control method, including: a precooling section, provided with a precooling component, for dehumidifying and cooling the fresh air entering the precooling section, the input end of the precooling section is provided with a fresh air temperature and humidity sensor, and the output end is provided with a precooling temperature sensor; a rotary dehumidifier, connected to the output end of the precooling section, and the input end of the rotary dehumidifier is provided with an air supply valve. Based on different dehumidification loads, this application fully considers the comprehensive energy-saving points of the system, so that the energy-saving rate of the clean environment temperature and humidity control system of the entire deep dehumidification is greatly improved. After project evaluation, the energy-saving rate is improved by at least 30% compared with the conventional control system before the transformation. Through the application of control methods such as the linkage of unit equipment and active optimization of target temperature, the temperature accuracy can be maintained within ±0.3°C for a long time, and the humidity accuracy can be maintained within ±3% for a long time.

Description

Technical Field

[0001] The present invention relates to the technical field of HVAC automation, and in particular to a temperature and humidity control system and a control method. Background Art

[0002] Environmental temperature and humidity control systems are commonly used in industries such as electronic semiconductors, biomedicine, and laboratories. For such manufacturing and scientific enterprises, they will first actively respond to the country's energy-saving and emission reduction requirements and require the energy-saving characteristics of the unit to be excellent; secondly, based on the product process, the environment has high-precision temperature and humidity control requirements, especially in the electronic semiconductor industry, which generally requires temperature within ±0.5℃ and humidity within ±5%.

[0003] The unit design in the prior art performs independent rotary dehumidification control on the fresh air or the unit performs rotary dehumidification control on the mixed air (fresh air + return air). The control method is that the rotary dehumidifier adjusts the heating valve output according to the preset value of the rotary outlet air temperature, and does not adaptively start and stop according to the change of environmental load or adaptively dynamically adjust the preset value of the rotary outlet air temperature, which leads to overload operation of the rotary dehumidifier under partial dehumidification load conditions, and the synchronous recooling valve and humidification valve will also be overloaded due to high temperature and low humidity caused by excessive dehumidification, which will cause huge energy waste and lead to a huge increase in the equipment operation costs of the enterprise.

[0004] In addition, during the transition season, this adjustment method of the rotary dehumidifier is prone to frequent starts and stops due to changes in the outdoor dehumidification load conditions. During the start-stop process, the indoor temperature and humidity oscillations caused by equipment lag and overshoot will cause the temperature and humidity control accuracy to exceed the standard, which cannot meet the high-precision environmental requirements of industries such as electronic semiconductors. Summary of the invention

[0005] In view of the technical problems existing in the temperature control system in the prior art, the first aspect of the present invention provides a temperature and humidity control system, comprising:

[0006] The pre-cooling section is provided with a pre-cooling component for dehumidifying and cooling the fresh air entering the pre-cooling section. The input end of the pre-cooling section is provided with a fresh air temperature and humidity sensor, and the output end is provided with a post-pre-cooling temperature sensor;

[0007] A rotary dehumidifier connected to the output end of the precooling section, and an air supply valve is provided at the input end of the rotary dehumidifier;

[0008] The air supply section comprises a recooling component, a heating component, a humidifying component and an air supply fan arranged in series, an output end of the air supply section is provided with an air supply temperature and humidity sensor, and the output end of the air supply section is connected to an indoor place;

[0009] The return air duct has its first end connected to an indoor area, and its second end connected to the primary return air duct and the secondary return air duct. The primary return air duct is connected to the output end of the pre-cooling section, and the secondary return air duct is connected to the input end of the air supply section. A return air temperature and humidity sensor is provided at the input end of the return air duct, and a primary return air valve is provided in the primary return air duct.

[0010] A controller is connected to the pre-cooling component, the air supply valve, the rotary dehumidifier, the re-cooling component, the heating component, the humidifying component, the air supply fan, and the primary return air valve.

[0011] Among them, the fresh air temperature and humidity sensor is used to detect the moisture content Fd of outdoor fresh air, the return air temperature and humidity sensor is used to detect the moisture content Rd of the return air in the indoor area, and the air supply temperature and humidity sensor is used to detect the moisture content Sd of the air supply.

[0012] The controller controls the operating states of the pre-cooling component and the rotary dehumidifier based on the moisture content Fd of outdoor fresh air.

[0013] The controller controls the opening degree of the primary return air valve based on the moisture content Rd of the return air.

[0014] The controller controls the operating states of the rotary dehumidifier, the re-cooling component, the heating component, and the humidifying component based on the moisture content Sd of the air supply, so that the moisture content Sd of the air supply meets the preset value.

[0015] Preferably, the pre-cooling component includes a pre-cooler, and a pre-cooling valve is provided on the pre-cooler. The pre-cooling valve is used to control the flow rate of the refrigerant in the pre-cooling section in the pre-cooler. The controller is connected to the pre-cooling valve and is used to control the opening degree of the pre-cooling valve.

[0016] Preferably, based on the fresh air temperature and humidity sensor, the fresh air enthalpy value h can be calculated, and based on the set temperature and humidity, the target cooling capacity Q can be calculated. If the designed cooling capacity Qs of the pre-cooler is greater than the target cooling capacity Q, the pre-cooling valve is preferentially controlled to dehumidify the fresh air through the pre-cooler. If the designed cooling capacity Qs of the pre-cooler is less than the target cooling capacity Q, the rotary dehumidifier is联动开启 (the specific meaning of this term needs to be further determined according to the context).

[0017] Preferably, the upper limit of the target moisture content is defined as Hd, and the lower limit of the target moisture content is defined as Ld.

[0018] When Rd > Hd, the controller controls the primary return air valve to open to 100% and turns on the rotary dehumidifier.

[0019] When Hd > Rd > Ld, the controller controls the opening degree K of the primary return air valve = (Rd - Ld) / (Hd - Ld).

[0020] When Rd < Ld, the controller controls the opening degree of the primary return air valve to be 0%.

[0021] Preferably, when Rd < Ld and Fd < Ld, the controller controls the opening degree of the primary return air valve to 100% and the opening degree of the supply air valve to 0%.

[0022] Preferably, the controller adjusts the states of the rotary dehumidifier and the pre-cooling component according to the set adjustment period T;

[0023] Among them, if the moisture content Sd of the supply air remains less than the lower limit Ld of the target moisture content, the controller preferentially lowers the outlet temperature of the rotary dehumidifier until the outlet temperature of the rotary dehumidifier reaches the lower limit value, and then raises the temperature after pre-cooling of the pre-cooling component, with the maximum not exceeding the target dry bulb humidity;

[0024] If the moisture content Sd of the supply air remains greater than the upper limit Hd of the target moisture content, the controller preferentially lowers the temperature after pre-cooling of the pre-cooling component, with the minimum not lower than the target dew point temperature, and then raises the outlet temperature of the rotary dehumidifier.

[0025] Preferably, within a complete adjustment period T, if the moisture content Sd of the supply air remains less than the lower limit Ld of the target moisture content, the controller reduces the outlet temperature of the rotary dehumidifier by a set fixed value. If the moisture content Sd of the supply air remains greater than the upper limit Hd of the target moisture content, the controller increases the outlet temperature of the rotary dehumidifier by a set fixed value.

[0026] Preferably, within a complete adjustment period T, if the moisture content Fd of the outdoor fresh air > the upper limit Hd of the target moisture content, the post-pre-cooling control temperature of the pre-cooling component is increased by a predetermined value, but the maximum does not exceed the target dry bulb temperature. If the moisture content Fd of the outdoor fresh air < the upper limit Hd of the target moisture content, the post-pre-cooling control temperature of the pre-cooling component is reduced by a predetermined value, with the minimum not lower than the target dew point temperature.

[0027] A technical solution is proposed in the second aspect of the present invention. A temperature and humidity control method uses the above temperature and humidity control system, including the following steps:

[0028] Step 1: Open the primary return air valve and the supply air valve;

[0029] Step 2: After the primary return air valve and the supply air valve are opened to 100%, start the supply air fan and perform constant air volume frequency conversion adjustment;

[0030] Step 3: When the indoor load and the outdoor load are fully mixed, perform active optimization control on the pre-cooling component, the supply air valve, the rotary dehumidifier, the re-cooling component, the heating component, the humidifying component, and the primary return air valve based on the indoor and outdoor load conditions to complete the system startup;

[0031] Step 4: When the system shuts down, preferentially close the pre-cooling component, the rotary dehumidifier, the re-cooling component, the heating component, and the humidifying component, and then close the supply air fan;

[0032] Step 5: After the air supply fan is completely shut down, close the return air valve and the air supply valve to complete the shutdown;

[0033] The active optimization control in the step includes the following steps:

[0034] Step a, obtaining the outdoor fresh air humidity content Fd, the return air humidity content Rd and the supply air humidity content Sd;

[0035] Step b, determine the relationship between the outdoor fresh air humidity Fd and the target humidity upper limit Hd, the target humidity Ld, determine the relationship between the return air humidity Rd and the target humidity upper limit Hd, the target humidity Ld, determine the relationship between the supply air humidity Sd and the target humidity upper limit Hd, the target humidity Ld, and determine the dehumidification load according to the above relationship, which is divided into a high dehumidification load state, a normal dehumidification load state, a low dehumidification load state and a no dehumidification load state;

[0036] Step c: according to different dehumidification load states, the pre-cooling component, the rotary dehumidifier, the re-cooling component, the heating component, the humidifying component, the air supply valve and the primary return air valve are adjusted.

[0037] Preferably, when the outdoor fresh air humidity Fd is greater than the target humidity upper limit Hd and / or the return air humidity Rd is greater than the target humidity upper limit Hd, it is in a high dehumidification load state, the primary return air valve is opened to %, the fresh air is controlled by the precooling component at the dew point temperature, and the rotary dehumidifier is started to control the mixed air of the fresh air and the return air;

[0038] When d<Fd<Hd and Hd>Rd>Ld, it is in the normal wet load state, and the opening degree of the primary return air valve K=Rd-Ld / Hd-Ld. Within the set adjustment period T, if the supply air humidity Sd remains less than the target humidity lower limit Ld, the rear outlet temperature of the rotary dehumidifier is preferentially lowered until the rear outlet temperature of the rotary dehumidifier reaches the lower limit, and then the pre-cooling temperature of the pre-cooling component is increased, and the maximum does not exceed the target dry-bulb humidity; if the supply air humidity Sd remains greater than the target humidity upper limit Hd, the pre-cooling temperature of the pre-cooling component is preferentially lowered, and the minimum is not less than the target dew point temperature, and then the rear outlet temperature of the rotary dehumidifier is increased;

[0039] When Ld<Rd<Hd and Fd<Ld, it is in a low dehumidification load state, the opening of the primary return air valve is K=Rd-Ld / Hd-Ld, and the opening of the supply air valve is 100%;

[0040] When Rd<Ld and Fd<Ld, it is in a state of no dehumidification load, the opening of the primary return air valve is 100%, and the opening of the supply air valve is 0%.

[0041] Preferably, if the supply air humidity content Sd remains less than the target humidity lower limit Ld, the controller lowers the outlet air temperature of the rotary dehumidifier by a set fixed value; if the supply air humidity content Sd remains greater than the target humidity upper limit Hd, the controller increases the outlet air temperature of the rotary dehumidifier by a set fixed value.

[0042] Preferably, within each adjustment cycle T, the fixed value of each adjustment of the rotary dehumidifier is 1°C, and the temperature adjustment value after precooling of the precooling component is 1°C.

[0043] Compared with the prior art, the advantages of the present invention are:

[0044] This application fully considers the comprehensive energy-saving points of the system based on different dehumidification loads, so that the energy-saving rate of the clean environment temperature and humidity control system of the entire deep dehumidification is greatly improved. After project evaluation, the energy-saving rate is increased by at least 30% compared with the conventional control system before the transformation. Through the application of control methods such as the linkage of unit equipment and active optimization of target temperature, the accuracy of all working conditions can be effectively guaranteed. After the evaluation of the transformation project, the temperature accuracy can be maintained within ±0.3℃ for a long time, and the humidity accuracy can be maintained within ±3% for a long time, which greatly meets the system requirements of the industrial environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For clarity, not every component is labeled in every figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings, in which:

[0046] Figure 1 It is a structural schematic diagram of the temperature and humidity control system shown in the present invention. DETAILED DESCRIPTION

[0047] In order to better understand the technical content of the present invention, specific embodiments are given and described as follows in conjunction with the accompanying drawings.

[0048] At present, the clean environment temperature and humidity control system for deep dehumidification usually designs the start-up of the rotary dehumidifier to be automatically interlocked when it is turned on, resulting in overload operation of the rotary dehumidifier under partial dehumidification load conditions. The synchronous re-cooling valve and humidification valve will also be overloaded due to high temperature and low humidity caused by excessive dehumidification. This will cause huge energy waste and lead to a huge increase in the company's equipment operating costs.

[0049] In addition, in southern my country, such as Fuzhou, the transition season often sees low temperatures in the morning and evening, and high temperatures and humidity at noon. Faced with this transition season, traditional control systems are prone to frequent starts and stops of equipment due to changes in outdoor dehumidification load conditions. During the start and stop process of the rotary dehumidifier, the indoor temperature and humidity oscillate due to equipment lag and overshoot, resulting in excessive temperature and humidity control accuracy, which cannot meet the high-precision environmental requirements of industries such as electronic semiconductors.

[0050] Combination Figure 1 As shown, the first aspect of the present invention proposes a temperature and humidity control system, especially a clean environment temperature and humidity control system with deep dehumidification. The system mainly includes a pre-cooling section, a rotary dehumidifier 5, an air supply section, a return air duct 21 and a controller 30.

[0051] The precooling section is provided with a precooling component 2 for dehumidifying and cooling the fresh air entering the precooling section. The input end of the precooling section is provided with a fresh air temperature and humidity sensor 1, and the output end is provided with a post-precooling temperature sensor 3.

[0052] The fresh air temperature and humidity sensor 1 is used to detect the fresh air dry-bulb temperature and relative humidity, and to calculate the fresh air enthalpy and moisture content.

[0053] Optionally, the precooling component 2 includes a precooler, the precooler is provided with a precooling valve, the precooling valve is used to control the flow of the refrigerant in the precooler in the precooling section, and the controller 30 is connected to the precooling valve for controlling the opening of the precooling valve.

[0054] In this way, the cooling capacity of the precooler can be controlled by controlling the opening of the precooling valve.

[0055] The post-precooling temperature sensor 3 is used to detect the post-precooling temperature and determine whether the precooling valve is properly controlled.

[0056] Furthermore, the rotary dehumidifier 5 is connected to the output end of the pre-cooling section, and the input end of the rotary dehumidifier 5 is provided with an air supply valve 4.

[0057] The rotary dehumidifier 5 is used to deeply dehumidify the system environment and can be linked to start and stop control. By controlling the power of the rotary dehumidifier 5, the preset value of the air outlet temperature after the rotary dehumidifier 5 can be adjusted.

[0058] Furthermore, the air supply section includes a re-cooling component 6, a heating component 7, a humidifying component 8 and an air supply fan 9 arranged in series, and an air supply temperature and humidity sensor 10 is provided at the output end of the air supply section, and the output end of the air supply section is connected to an indoor place.

[0059] The cooling component 6 is used to control the cooling of the mixed air after the rotary dehumidifier, the heating component 7 is used to control the heating of the mixed air after the rotary dehumidifier, and the humidifying component 8 is used to control the humidification of the mixed air after the rotary dehumidifier. The air supply fan 9 is frequency-controlled based on the target air supply volume to make the air supply volume reach the target value. A air supply volume sensor is also provided at the end of the air supply section to detect the air supply volume of the air supply fan 9.

[0060] It should be understood that the working air outlet temperature of the rotary dehumidifier 5 is generally about 40°C. After the rotary dehumidifier 5 is working, the cooling component 6 needs to cool the air outlet temperature of the rotary dehumidifier 5 to reduce the temperature to the target temperature. If the temperature is too low, the heating component 7 can also be used to increase the temperature. In addition, if the moisture content is too low due to dehumidification, it is necessary to replenish the moisture through the humidification component 8 to add the humidity to the target moisture content to achieve the effect of energy saving and precise control.

[0061] Furthermore, the first end of the return air duct 21 is connected to an indoor place, and the second end is connected to a primary return air duct 23 and a secondary return air duct 22. The primary return air duct 23 is connected to the output end of the pre-cooling section, and the secondary return air duct 22 is connected to the input end of the air supply section. The input end of the return air duct 21 is provided with a return air temperature and humidity sensor 25, and the primary return air duct 23 is provided with a primary return air valve 24.

[0062] Among them, the controller 30 is connected to the pre-cooling component 2, the supply air valve 4, the rotary dehumidifier 5, the re-cooling component 6, the heating component 7, the humidification component 8, the supply air fan 9, the primary return air valve 24, the return air temperature and humidity sensor 25, the fresh air temperature and humidity sensor 1, and the supply air temperature and humidity sensor 10.

[0063] The fresh air temperature and humidity sensor 1 is used to detect the outdoor fresh air humidity Fd, the return air temperature and humidity sensor 25 is used to detect the return air humidity Rd in the indoor place, and the supply air temperature and humidity sensor 10 is used to detect the supply air humidity Sd.

[0064] In this way, by collecting the outdoor fresh air humidity content Fd, return air humidity content Rd and supply air humidity content Sd, the humidity content of fresh air, return air, mixed air and outlet air can be judged and the currently required dehumidification capacity can be evaluated.

[0065] For the outdoor fresh air load, the controller 30 can control the operating status of the pre-cooling component 2 and the rotary dehumidifier 5 based on the outdoor fresh air humidity content Fd.

[0066] Specifically, the humidity content of the outdoor air is calculated based on the fresh air temperature and humidity sensor 1, and compared with the humidity content calculated based on the set temperature and humidity. When the outdoor humidity content is greater than the set humidity content, the outdoor load is calculated as follows:

[0067] Based on the fresh air temperature and humidity, the fresh air enthalpy value h1 can be calculated;

[0068] The set dew point temperature can be calculated based on the set temperature and humidity. Based on the dew point temperature and 95% relative humidity, the target enthalpy value h2 of the surface cooling air outlet required after surface cooling can be calculated.

[0069] Based on the supply air volume V and the difference between the fresh air enthalpy value h1 and the outlet air target enthalpy value h2, the target cooling capacity Q that the system needs to output can be calculated. The mathematical expression is as follows:

[0070] Q=ρ*V*[h1-h2]

[0071] Among them, Q is the target cooling capacity, ρ is the air density, V is the supply air volume, h1 is the fresh air enthalpy value, and h2 is the target enthalpy value of the surface cooling air outlet;

[0072] Based on the target cooling capacity Q, if the design cooling capacity Qs of the pre-cooling section is greater than or equal to the target cooling capacity Q, the pre-cooling valve is opened first to cool and dehumidify; if the design cooling capacity Qs of the pre-cooling section is less than the target cooling capacity Q, the rotary dehumidifier 5 needs to be started in conjunction.

[0073] Regarding the return air load of the indoor location, the controller 30 controls the opening degree of the primary return air valve 24 based on the return air humidity content Rd.

[0074] Specifically, the humidity of the indoor air is calculated based on the return air temperature and humidity sensor 25, and compared with the humidity calculated based on the set temperature and humidity. When the indoor humidity is greater than the set upper humidity limit, the rotary dehumidifier 5 needs to be started in conjunction, and the opening of the return air valve 24 is dynamically adjusted based on the indoor humidity. The calculation is as follows:

[0075] Based on the target temperature and the temperature control accuracy dead zone Dt, the target temperature upper limit Ht and the target temperature lower limit Lt are calculated;

[0076] Among them, the upper temperature limit Ht = target temperature t + temperature dead zone Dt; the lower temperature limit Lt = target temperature t - temperature dead zone Dt.

[0077] For example: if the temperature dead zone is ±1°C and the target temperature is 23°C, then the upper limit of the target temperature is 24°C and the lower limit of the target temperature is 22°C.

[0078] Based on the target humidity and the humidity control accuracy dead zone Dh, the target humidity upper limit Hh and the target humidity lower limit Lh are calculated;

[0079] Among them, the upper limit of humidity Hh = target humidity h + humidity dead zone Dh; the lower limit of humidity Lh = target humidity h - humidity dead zone Dh.

[0080] For example: if the humidity dead zone is ±5% and the target humidity is 50%, then the upper limit of the target humidity is 55% and the lower limit of the target humidity is 45%.

[0081] Calculate the target upper limit of moisture content Hd based on the target upper limit of temperature Ht and the target upper limit of moisture content Hh;

[0082] Among them, the calculation of the target moisture content upper limit Hd, the target temperature upper limit Ht and the target moisture content upper limit Hh.

[0083] Based on the following formula:

[0084] Pv=611.2*e(18.678-Td / 234.5)*Td / (Td+257.14) (1.1)

[0085] d=0.6219*0.01*Hr*Pv / (101326-0.01Hr*Pv)*1000 (1.2)

[0086] Td is the dry bulb temperature, Hr is the relative humidity, Pv is the water vapor partial pressure, and d is the moisture content.

[0087] According to equations (1.1) and (1.2), substitute Ht into Td, Hh into Hr, and Hd into d.

[0088] Based on the target temperature lower limit Lt and the target moisture content lower limit Lh, the target moisture content lower limit Ld is calculated;

[0089] Among them, the calculation of the target moisture content lower limit Ld, the target temperature lower limit Lt and the target moisture content lower limit Lh.

[0090] According to equations (1.1) and (1.2), substitute Lt into Td, Lh into Hr, and Ld into d.

[0091] The indoor humidity Rd is calculated based on the return air temperature and humidity. The return air humidity Rd, return air temperature Rt and return air humidity Rh are calculated according to (1.1) and (1.2), substituting Rt into Td, Rh into Hr and Rd into d.

[0092] The indoor humidity Rd is linearly compared with the target humidity upper limit Hd and the target humidity lower limit Ld. When the indoor humidity Rd is greater than or equal to the target humidity upper limit Hd, the primary return air valve 24 is fully opened to 100%; when the indoor humidity Rd is less than or equal to the target humidity lower limit Ld, the primary return air valve 24 is fully closed to 0%; when the indoor humidity Rd is greater than the target humidity lower limit Ld and less than the target humidity Hd, the formula is as follows:

[0093] The opening degree K of the primary return air valve 24 is adjusted dynamically.

[0094] The working condition of the rotary dehumidifier can be linked to the outdoor and indoor load demands, and the temperature and humidity load of the air supply can be adjusted based on the processed air supply temperature and humidity load.

[0095] Dynamically adjust the outlet temperature target of the rotary dehumidifier (generally, the outlet temperature of the rotary dehumidifier is about 40°C. After the rotary dehumidifier is working, the cooling valve needs to cool the outlet temperature of the rotary dehumidifier to the target temperature. In addition, if the moisture content is too low due to dehumidification, it is necessary to add moisture through the humidification valve to increase the humidity to the target moisture content) to achieve energy saving and precise control effects. The calculation is as follows:

[0096] Based on the temperature and humidity detected by the air supply temperature and humidity sensor 9, the air supply humidity Sd is calculated, wherein the air supply humidity Sd, the air supply temperature St and the air supply humidity Sh are calculated. According to formula (1.1) and formula (1.2), St is substituted into Td, Sh is substituted into Hr, and Sd is substituted into d.

[0097] Furthermore, the controller 30 controls the operating states of the rotary dehumidifier 5, the recooling component 6, the heating component 7 and the humidifying component 8 based on the supply air humidity content Sd, so that the supply air humidity content Sd meets a preset value.

[0098] Optionally, the controller 30 adjusts the states of the rotary dehumidifier 5 and the precooling component 2 according to a set adjustment period T;

[0099] If the air supply humidity Sd remains lower than the target humidity lower limit Ld, the outlet temperature of the rotary dehumidifier 5 is preferentially lowered until the outlet temperature of the rotary dehumidifier 5 reaches the lower limit, and then the precooling temperature of the precooling component 2 is raised, and the maximum does not exceed the target dry-bulb humidity.

[0100] If the air supply humidity Sd remains greater than the target upper humidity limit Hd, the pre-cooling temperature of the pre-cooling component 2 is preferentially lowered to a minimum temperature not lower than the target dew point temperature, and then the outlet temperature of the rotary dehumidifier 5 is raised.

[0101] Among them, within a complete adjustment cycle T, if the supply air humidity Sd remains lower than the target humidity lower limit Ld, the controller 30 will reduce the outlet air temperature of the rotary dehumidifier 5 by a set fixed value; if the supply air humidity Sd remains greater than the target humidity upper limit Hd, the controller 30 will increase the outlet air temperature of the rotary dehumidifier 5 by a set fixed value.

[0102] When the control system has adjusted the target air outlet temperature of the rotary dehumidifier to the minimum value, it means that the system dehumidification load is low. How to achieve precision and energy-saving control under low load is calculated as follows:

[0103] The surface cooling valve is precisely controlled based on the temperature after precooling. When the outdoor fresh air humidity Fd> the target humidity upper limit Hd, it needs to be controlled based on the set dew point temperature. When the system dehumidification load is small, the temperature control target value after precooling is dynamically increased by 1°C after each adjustment cycle T, and the maximum value does not exceed the target dry bulb temperature. On the contrary, the temperature control target value after precooling is dynamically reduced by 1°C after each adjustment cycle T, and the minimum value is not lower than the target dew point temperature.

[0104] In summary, by controlling the outlet temperature of the precooling valve under dynamic load, the output of the surface cooler in the precooling section can be effectively reduced, and the temperature and humidity accuracy regulation under low-load dehumidification requirements can be ensured.

[0105] In addition, when the dehumidification load is low or there is no dehumidification load, the primary return air valve 24 is opened, and the opening is dynamically adjusted based on the indoor dehumidification load demand. The supply air valve 4 is opened to 100%, and the fresh air is mixed with the primary return air and deep dehumidification is performed through the rotary dehumidifier 5.

[0106] When the system has no dehumidification load demand, the primary return air valve 24 is opened to 100% and the supply air valve 4 is closed to 0%. At this time, the fresh air passes through the primary return air valve 24 and is mixed with the secondary return air, skipping the rotary dehumidifier 5 and directly entering the re-cooling section. This can effectively avoid the increase in the output of the re-cooling section surface cooling valve caused by the increase in the outlet air temperature after the mixed air passes through the rotary dehumidifier, thereby achieving a certain energy-saving effect.

[0107]

Temperature and humidity control method

[0108] The second aspect of the present invention proposes a technical solution, a temperature and humidity control method, using the above-mentioned temperature and humidity control system, comprising the following steps:

[0109] Step 1, open the primary return air valve 24 and the supply air valve 4;

[0110] Step 2: After the primary return air valve 24 and the air supply valve 4 are opened to 100%, the air supply fan 9 is started to perform constant air volume variable frequency regulation;

[0111] Step 3: After the indoor load and the outdoor load are fully mixed, the pre-cooling component 2, the air supply valve 4, the rotary dehumidifier 5, the re-cooling component 6, the heating component 7, the humidifying component 8, and the primary return air valve 24 are actively optimized based on the indoor and outdoor load conditions to complete the system startup;

[0112] Step 4: When the system is shut down, the pre-cooling component 2, the rotary dehumidifier 5, the re-cooling component 6, the heating component 7 and the humidifying component 8 are turned off first, and then the air supply fan 9 is turned off;

[0113] Step 5: After the air supply fan 9 is completely shut down, close the return air valve 24 and the air supply valve 4 to complete the shutdown;

[0114] The active optimization control in step 3 includes the following steps:

[0115] Step a, obtaining the outdoor fresh air humidity content Fd, the return air humidity content Rd and the supply air humidity content Sd;

[0116] Step b, determine the relationship between the outdoor fresh air humidity Fd and the target humidity upper limit Hd and the target humidity d, determine the relationship between the return air humidity Rd and the target humidity upper limit Hd and the target humidity d, determine the relationship between the supply air humidity Sd and the target humidity upper limit Hd and the target humidity d, and determine the dehumidification load according to the above relationship, which is divided into a high dehumidification load state, a normal dehumidification load state, a low dehumidification load state and a no dehumidification load state;

[0117] Step c: according to different dehumidification load states, the pre-cooling component 2, the rotary dehumidifier 5, the re-cooling component 6, the heating component 7, the humidifying component 8, the air supply valve 4 and the primary return air valve 24 are adjusted.

[0118] Preferably, when the outdoor fresh air humidity Fd is greater than the target humidity upper limit Hd and / or the return air humidity Rd is greater than the target humidity upper limit Hd, it is in a high dehumidification load state, the primary return air valve 24 is opened to 100%, the fresh air is controlled at the dew point temperature by the precooling component 2, and the rotary dehumidifier 5 is started to control the mixed air of the fresh air and the return air;

[0119] When d<Fd<Hd and Hd>Rd>Ld, it is in normal wet load state, the opening degree K of the primary return air valve 24 is Rd-Ld / Hd-Ld, within the set adjustment period T, if the supply air humidity Sd remains less than the target humidity lower limit Ld, the outlet temperature of the rotary dehumidifier 5 is preferentially lowered until the outlet temperature of the rotary dehumidifier 5 reaches the lower limit, and then the pre-cooling temperature of the pre-cooling component 2 is increased, and the maximum does not exceed the target dry-bulb humidity; if the supply air humidity Sd remains greater than the target humidity upper limit Hd, the pre-cooling temperature of the pre-cooling component 2 is preferentially lowered, and the minimum is not lower than the target dew point temperature, and then the outlet temperature of the rotary dehumidifier 5 is increased.

[0120] Among them, if the supply air humidity content Sd remains lower than the target humidity lower limit Ld, the controller 30 will reduce the outlet air temperature of the rotary dehumidifier 5 by a set fixed value; if the supply air humidity content Sd remains greater than the target humidity upper limit Hd, the controller 30 will increase the outlet air temperature of the rotary dehumidifier 5 by a set fixed value.

[0121] Specifically, when adjusting the rotary dehumidifier, within the adjustment cycle T, when the supply air humidity Sd remains less than the target humidity lower limit Ld, the outlet air temperature target of the rotary dehumidifier is reduced by 1°C each time the adjustment cycle T passes, and the cooling output of the recooling valve and the humidification output of the humidification valve are reduced, thereby achieving energy saving. Conversely, within the adjustment cycle T, when the supply air humidity Sd continues to be greater than the target humidity upper limit Hd, the outlet air temperature target of the rotary dehumidifier is increased by 1°C each time the adjustment cycle T passes, to ensure the precise control effect of the system dehumidification.

[0122] Specifically, when the precooling component 2 is adjusted, the temperature control target value after precooling is dynamically increased by 1°C within the adjustment cycle T, and the maximum value does not exceed the target dry bulb temperature. Conversely, after each adjustment cycle T, the temperature control target value after precooling is dynamically reduced by 1°C, and the minimum value does not fall below the target dew point temperature.

[0123] When d<Rd<Hd and Fd<d, it is in a low dehumidification load state, the opening degree of the primary return air valve 24 is K=Rd-Ld / Hd-Ld, and the opening degree of the supply air valve is 100%.

[0124] When Rd<d and Fd<d, it is in a state of no dehumidification load, the opening of the primary return air valve 24 is 100%, and the opening of the supply air valve is 0%.

[0125] The deep dehumidification unit proposed in this application can continuously and adaptively adjust the system control strategy for frequently changing operating conditions such as transition seasons, and find the optimal control point under different dehumidification load scenarios to achieve the goals of energy saving and high-precision temperature and humidity control. The indoor temperature accuracy can be maintained at ±0.3℃ all day long, and the indoor humidity accuracy can be maintained at ±3%.

[0126] In combination with the above embodiments, this application fully considers the comprehensive energy-saving points of the system based on different dehumidification loads, so that the energy saving rate of the clean environment temperature and humidity control system of the entire deep dehumidification is greatly improved. After project evaluation, the energy saving rate is increased by at least 30% compared with the conventional control system before the transformation. Through the application of control methods such as the linkage of unit equipment and active optimization of target temperature, the accuracy of all working conditions can be effectively guaranteed.

[0127] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A temperature and humidity control system, characterized in that: include: A precooling section is provided with a precooling component (2) for dehumidifying and cooling the fresh air entering the precooling section, wherein the input end of the precooling section is provided with a fresh air temperature and humidity sensor (1), and the output end is provided with a post-precooling temperature sensor (3); A rotary dehumidifier (5) is connected to the output end of the pre-cooling section, and an air supply valve (4) is provided at the input end of the rotary dehumidifier (5); An air supply section comprises a recooling component (6), a heating component (7), a humidifying component (8) and an air supply fan (9) arranged in series, wherein an output end of the air supply section is provided with an air supply temperature and humidity sensor (10), the output end of the air supply section is connected to an indoor location, and the input end of the air supply section is connected to the output end of the rotary dehumidifier (5); A return air duct (21), a first end of which is connected to an indoor location, and a second end of which is connected to a primary return air duct (23) and a secondary return air duct (22), wherein the primary return air duct (23) is connected to the output end of the precooling section, and the secondary return air duct (22) is connected to the input end of the air supply section, a return air temperature and humidity sensor (25) is provided at the input end of the return air duct (21), and the primary return air duct (23) is provided with a primary return air valve (24); A controller (30) connected to the pre-cooling component (2), the air supply valve (4), the rotary dehumidifier (5), the re-cooling component (6), the heating component (7), the humidifying component (8), the air supply fan (9), and the primary return air valve (24); The fresh air temperature and humidity sensor (1) is used to detect the outdoor fresh air humidity Fd, the return air temperature and humidity sensor (25) is used to detect the return air humidity Rd in the indoor place, and the supply air temperature and humidity sensor (10) is used to detect the supply air humidity Sd; The controller (30) controls the operating states of the precooling component (2) and the rotary dehumidifier (5) based on the outdoor fresh air humidity content Fd; The controller (30) controls the opening of the primary return air valve (24) based on the return air humidity content Rd; The controller (30) controls the operating states of the rotary dehumidifier (5), the recooling component (6), the heating component (7) and the humidifying component (8) based on the supply air humidity content Sd, so that the supply air humidity content Sd meets a preset value; The controller (30) adjusts the states of the rotary dehumidifier (5) and the precooling component (2) according to a set adjustment cycle T; If the supply air humidity Sd remains lower than the target humidity lower limit Ld, the outlet air temperature of the rotary dehumidifier (5) is preferentially lowered until the outlet air temperature of the rotary dehumidifier (5) reaches the lower limit, and then the pre-cooling temperature of the pre-cooling component (2) is raised, with the maximum temperature not exceeding the target dry-bulb humidity. If the supply air humidity Sd remains greater than the target upper humidity limit Hd, the precooling temperature of the precooling component (2) is preferentially lowered to a minimum temperature not lower than the target dew point temperature, and then the outlet air temperature of the rotary dehumidifier (5) is raised.

2. The temperature and humidity control system according to claim 1, characterized in that: The precooling component (2) comprises a precooler, the precooler is provided with a precooling valve, the precooling valve is used to control the flow of the refrigerant in the precooler in the precooling section, and the controller (30) is connected to the precooling valve and is used to control the opening of the precooling valve.

3. The temperature and humidity control system according to claim 2, characterized in that: Based on the fresh air temperature and humidity sensor (1), the enthalpy value h1 of the fresh air can be calculated. Based on the set temperature and humidity, the target cooling capacity Q can be calculated. If the designed cooling capacity Qs of the precooler is greater than the target cooling capacity Q, the precooling valve is preferentially controlled to dehumidify the fresh air through the precooler. If the designed cooling capacity Qs of the precooler is less than the target cooling capacity Q, the rotary dehumidifier (5) is linked and started.

4. The temperature and humidity control system according to claim 1, characterized in that: Define the upper limit of the target moisture content as Hd and the lower limit of the target moisture content as Ld; When Rd > Hd, the controller (30) controls the primary return air valve (24) to open to 100% and starts the rotary dehumidifier (5); When Hd > Rd > Ld, the controller (30) controls the opening degree K of the primary return air valve (24) = (Rd - Ld) / (Hd - Ld); When Rd < Ld, the controller (30) controls the opening degree of the primary return air valve (24) to be 0%; 5. The temperature and humidity control system according to claim 4, characterized in that: When Rd < Ld and Fd < Ld, the controller (30) controls the opening degree of the primary return air valve (24) to be 100% and the opening degree of the supply air valve (4) to be 0%; 6. The temperature and humidity control system according to claim 1, characterized in that: Within a complete adjustment cycle T, if the supply air moisture content Sd remains less than the lower limit Ld of the target moisture content, the controller (30) reduces the outlet air temperature of the rotary dehumidifier (5) by a set fixed value. If the supply air moisture content Sd remains greater than the upper limit Hd of the target moisture content, the controller (30) increases the outlet air temperature of the rotary dehumidifier (5) by a set fixed value.

7. The temperature and humidity control system according to claim 1, characterized in that: Within a complete adjustment cycle T, if the outdoor fresh air moisture content Fd > the upper limit Hd of the target moisture content, the temperature after precooling of the precooling component (2) is increased by a predetermined value, but not exceeding the target dry bulb temperature at most. If the outdoor fresh air moisture content Fd < the upper limit Hd of the target moisture content, the temperature after precooling of the precooling component (2) is decreased by a predetermined value, not lower than the target dew point temperature at least.

8. A temperature and humidity control method, characterized in that: Using the temperature and humidity control system according to any one of claims 1 - 7, comprising the following steps: Step 1: Open the primary return air valve (24) and the supply air valve (4); Step 2: After the primary return air valve (24) and the supply air valve (4) are opened to 100%, start the supply air fan (9) and perform constant air volume frequency conversion adjustment; Step 3: After the indoor load and the outdoor load are fully mixed, perform active optimization control on the precooling component (2), the supply air valve (4), the rotary dehumidifier (5), the reheating component (6), the heating component (7), the humidifying component (8), and the primary return air valve (24) based on the indoor and outdoor load conditions to complete the system startup; Step 4: When the system shuts down, preferentially close the precooling component (2), the rotary dehumidifier (5), the reheating component (6), the heating component (7), and the humidifying component (8), and then close the supply air fan (9); Step 5: After the supply air fan (9) is completely closed, close the primary return air valve (24) and the supply air valve (4) to complete the shutdown; Among them, the active optimization control in step 3 includes the following steps: Step a: Obtain the outdoor fresh air moisture content Fd, the return air moisture content Rd, and the supply air moisture content Sd; Step b, determine the relationship between the outdoor fresh air humidity Fd and the target humidity upper limit Hd and the target humidity lower limit Ld, determine the relationship between the return air humidity Rd and the target humidity upper limit Hd and the target humidity lower limit Ld, determine the relationship between the supply air humidity Sd and the target humidity upper limit Hd and the target humidity lower limit Ld, and determine the dehumidification load according to the above relationship, which is divided into a high dehumidification load state, a normal dehumidification load state, a low dehumidification load state and a no dehumidification load state; Step c: adjusting the pre-cooling component (2), the rotary dehumidifier (5), the re-cooling component (6), the heating component (7), the humidifying component (8), the air supply valve (4) and the primary return air valve (24) according to different dehumidification load states.

9. The temperature and humidity control method according to claim 8, characterized in that: When the outdoor fresh air humidity Fd is greater than the target humidity upper limit Hd and / or the return air humidity Rd is greater than the target humidity upper limit Hd, the system is in a high dehumidification load state, the primary return air valve (24) is opened to 100%, the fresh air is controlled at the dew point temperature through the precooling component (2), and the rotary dehumidifier (5) is started to control the mixed air of the fresh air and the return air; When Ld<Fd<Hd and Hd>Rd>Ld, it is in a normal wet load state, and the opening degree K of the primary return air valve (24) is K=(Rd-Ld) / (Hd-Ld). Within the set adjustment period T, if the supply air humidity Sd remains less than the target humidity lower limit Ld, the outlet air temperature of the rotary dehumidifier (5) is preferentially lowered until the outlet air temperature of the rotary dehumidifier (5) reaches the lower limit, and then the pre-cooling temperature of the pre-cooling component (2) is increased, and the maximum value does not exceed the target dry-bulb humidity; if the supply air humidity Sd remains greater than the target humidity upper limit Hd, the pre-cooling temperature of the pre-cooling component (2) is preferentially lowered, and the minimum value is not less than the target dew point temperature, and then the outlet air temperature of the rotary dehumidifier (5) is increased; When Ld<Rd<Hd and Fd<Ld, it is in a low dehumidification load state, the opening degree of the primary return air valve (24) is K=(Rd-Ld) / (Hd-Ld), and the opening degree of the supply air valve is 100%; When Rd<Ld and Fd<Ld, it is in a state of no dehumidification load, the opening of the primary return air valve (24) is 100%, and the opening of the supply air valve is 0%.

10. The temperature and humidity control method according to claim 9, characterized in that: In each adjustment cycle T, if the supply air humidity Sd remains less than the target humidity lower limit Ld, the controller (30) reduces the outlet air temperature of the rotary dehumidifier (5) by a set fixed value; if the supply air humidity Sd remains greater than the target humidity upper limit Hd, the controller (30) increases the outlet air temperature of the rotary dehumidifier (5) by a set fixed value.

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